Blue EV bar missing when car is in EV mode

@craze1cars, it doesn’t make sense to me either for Honda to have the ICE come on when the battery is full and the BMS is protecting it from overcharging. However it is an observable, reproducible fact that I and many other posters have reported. So am am convinced that it is happening. It’s just too coincidental that in 1,700 miles (since last ICE operation), it only does it only and immediately after a full charge and just when I hit the brake hard.

At first, I just chalked it up to the System Check mentioned in the manual, but then I began to notice that almost all of the time it happened immediately after a full charge and a heavy brake or calling for 4 chevron regen. Also, my hour meter increments, the ICE gets warm to the touch, and I can hear the ICE running for about 5 min.
So I don’t know why Honda set it up this way or exactly how it works, but it is a real event.
@insightman has posted a lot on this and some one posted a tech paper that vindicated @insightman’s theory but I can’t find it.

 

I'm certainly not saying it doesn't happen in those circumstances...I've experienced it too, just a couple times.

I'm just one of those guys who generally understands how things work and why, especially with cars. I'm a mechanic/builder/handyman and spent decades as an auto claim adjuster heavily involved in troubleshooting and handling all types of strange repair situations caused by accidents, flooding, abuse, neglect, mechanical/electrical failure, and whatever. I've done frame-off restorations on classics, and I understand generators and electric motors and have fixed/rebuilt some of them too.

For example I feel I have my head wrapped well around the when/where/why of the angry bees thing...and I have no problem with them because I respect and understand what the engine is doing in those circumstances they get stirred up, how long it takes them to fade away in differing circumstances, and from a programming perspective I also understand why it periodically happens.

But this thing I simply can't wrap my head around. I would be interested in seeing whatever technical paper was found, assuming it was something from Honda. I assure everyone I have an open mind about this, and mostly just am curious to learn more...my intent is not to argue anything. But right now I can't fathom any electrical or mechanical benefit to starting the engine, for the simple reason that the battery is full and someone hits the brakes and the battery needs protection from regen power. Should the car cut off the charge flow to the battery? Yes absolutely! But why start the engine to accomplish this? How does that benefit the process in any way? I can't buy engine braking as an explanation, because during these starts in my experience, the car has been going slower speeds and is uncoupled from the drivetrain! And on fast mountain descents the engine never even turned on!

So I haven't yet heard a solid reason that I can understand. In my mind it's just another of several little glitches in the car, that probably would benefit from a reprogramming fix.

And really this should be a different topic than I'm writing in...I'm so sorry for derailing this thread from original intent of the original poster's question about the blue bar...my apologies.

 

I ag

I agree with you completely, but the facts are fairly indisputable so I have to deal with them. And I would pay good money to know the why and how of this. @insightman has proposed a decent theory but up to now we have no proof, we just know it happens. I’ll search tonight for that article and maybe someone will link to it for us.
And don’t worry about derailing the thread; I can assure you that we regularly hijack threads on this forum in a much worse manner!

 

This is the thread with referenced material linked in various posts.
https://insideevsforum.com/community/index.php?threads/solved-unexpected-ice-turns-on.3402/

 

In the owners manual, in the early section where it explains about the System Test it says there that even though only the EV light is on, the power meter would still show the white dashed lines for awhile before returning to blue.

 

I’ve read that. The reason I think it’s sometimes not a System Check is that it happens exactly upon hard braking immediately after a full charge.

And @ab13, thanks for finding and reposting that link. It also corroborates that somehow turing on the ICE is used to dissipate the regen power when the battery shouldn’t take any more charge and keep from over charging the battery. That hypothesis was first posted by @insightman.

 

When the battery is fully charged, all of Honda's i-MMD hybrid cars run the starter motor/generator to use up the power generated by the traction motor operating as a brake to slow the car. In the Accord Hybrid and the Insight, the starter motor/generator spins a deadened engine (no fuel, valves closed), but that technique evidently doesn't use up as much power as the Clarity PHEV needs to dissipate.

To use up more regenerated power, the Clarity PHEV had to provide more resistance to the starter motor/generator than is available from a deadened engine. As many posters have noted, the Clarity PHEV starts its engine if the battery is fully charged when regen braking is initiated. So how can a running engine provide greater resistance than a deadened engine? My theory is that the Clarity PHEV switches the torque generated by the starter motor/generator to OPPOSE the torque generated by the running engine.

It certainly doesn't seem to make sense for an efficiency-oriented car to burn fuel to use up excess electricity, but Honda's engineers didn't see a better option after determining the Clarity PHEV needed to dissipate more power than would be possible using the deadened-engine scheme.

 

They could have just caused a disconnect and use friction brakes until the battery was able to accept charge.

 

Honda wanted an alternative to glowing red brake discs on mountain descents.

 

Well, now that my EV range is barely enough, a few times I end in HV mode for the last couple of miles, after getting to zero EV. But what I noticed is that when braking, I can feel the brakes more than at other times. I actually feel a slight vibration as if there's a small warp in the rotors. The regen marker stays at almost zero as well. Even if I use the paddles, the indicator blinks and won't go past 3 chevrons. If the batteries are down to 10% why can't the car use full regen?

 

I don’t know, but it could be cold temps. If battery is too cold it is not healthy to charge it too quickly. These cars have a good amount of quirks and downsides in cold temps. And a notable loss of efficiency. Also some cool benefits like instant heat and preconditioning with electricity on level 2 chargers. Potential owners should consider all this. As I tell everyone who rides along with me and starts wondering about it, I often find myself saying “it’s an odd car...”.

I freely admit I overall like the car better in warmer weather.

 

The Clarity PHEV's braking system is so complex, it even has a "Pedal Feel Simulator!"

 

Yes, THIS. I bought my car in January last year and put up with several quirks when it was new because I didn't know any better. After really enjoying the benefits of owning an EV for a year, the return to ultra-cold temperatures (single digit F in Duluth, Minnesota) has got me irritated about several things about how poorly (relatively) the car performs in cold weather:

1. The range is absolutely shot. I was regularly getting 50 miles of EV range. Now, it is in the 20s. On very cold weeks, my "real" range (after use of heating) is sometimes only 19 miles or less.

2. On very cold days, the ICE comes on as soon as I hit the START button. Since my drive to work is barely 3 miles, I nowadays go to work and return from work without ever being in pure EV mode. I'm stuck using gas all the time. Sometimes, I';ve even been on longer drives (10+ miles where the ICE stays on).

3. The "dashed white line" stays on even when the ICE occasionally shuts off when in some cold-weather conditions.

4. HV mode trips (100+ miles) have resulted in my averaging about 36 mpg. Pretty sad.

5. Charging at work (240 V) has become unbearably slow. It charges now at less than 2 kW which really is a trickle.

The car is SO MUCH more fun in warm weather.

 

The reason i got a new car was so i could give my 2012 Prius Plugin to my technophobe daughter. She called me whining that she could not get down the street these days even with a full battery without the ICE turning on. I explained that even with the heating off the car would start out the day in cold weather by turning on the ICE for a while because...wake up. On the second trip of the day, it would go EV unless you wanted heat which ran off the ICE.

It will get warm again and then we will be in our Clarity glory.

 

It’s not quite as cold here in Boston as Minnesota, but I find I get much better range if I use the remote climate control for 15 minutes while plugged in.

 

Maybe it is a small warp in the rotors?

I ask because in about 2 months of ownership mine has never exhibited this behavior.

 

Noticed this yesterday again, this time, with about 60% of battery left. Was driving in HV mode, about 35-40 mph. Decided to coast, and regened to level 4. But it would blink and stay at level 3. The meter on the dashboard would not go more than 1/4 down the green. Tried Sports mode, and even then, it would not go past level 3.

Pressing the brake pedal, I could feel the car actually braking more than other times when I use regen. Vibration was almost gone so if there's a warp, is very minor. Maybe it was rust buildup the previous time.

I waited until the car got onto EV mode by itself, and turned off HV mode. Then regen worked fine without issues. It sounds as if the ICE was recharging the batteries already too much, so regen could not do it? Doesn't make sense, but then again, there's many things with this car that doesn't..